Special proteins guard the surface of cells to prevent the body’s own immune system attacking them.

In a study published in Cell Reports, researchers developed and tested the cancer-fighting antibody.

The human-derived anitibody dismantles a specific part of the cancer cell’s defence system, before launching an attack.

The team began their research after observing that some lung cancer patients have early-stage tumours that never progress to advanced stages.

The patients with the slower-progressing tumours had antibodies against a specific protein, called complement factor H, or CFH, which protects cells from an immune system attack.

CFH prevents an important immune system response from activating.

After identifying the antibody for CFH, researchers from Duke University, North Carolina, then developed a way to replicate the autoantibodies made by the early-stage cancer patients.

These mature antibodies recognised the same region of CFH targeted by the original patient’s immune systems, so healthy cells were left unharmed.

The team went on to test the new treatment on multiple cancer cell lines, including lung, gastric and breast cancers.

Author Dr Edward Patz, from Duke University,said: “This is the first completely human-derived antibody developed as an anti-cancer therapy, which is very different from other immunotherapy approaches.

“We believe it might be this additional cellular response that could potentially have the most profound impact on cancer outcomes long-term.”

While researchers say further tests are needed, the team are excited about the new findings.

Dr Patz added: “This could represent a whole new approach to treating cancer, and it’s exciting because the antibody selectively kills tumour cells, so we don’t have significant side effects to achieve tumour control.

“We believe we can modulate the immune response and let the body’s own immune system take over to either kill the tumour or keep it from growing.”